Follow Techotopia on Twitter

On-line Guides
All Guides
eBook Store
iOS / Android
Linux for Beginners
Office Productivity
Linux Installation
Linux Security
Linux Utilities
Linux Virtualization
Linux Kernel
System/Network Admin
Scripting Languages
Development Tools
Web Development
GUI Toolkits/Desktop
Mail Systems
Eclipse Documentation

How To Guides
General System Admin
Linux Security
Linux Filesystems
Web Servers
Graphics & Desktop
PC Hardware
Problem Solutions
Privacy Policy




Red Hat Enterprise Linux 9 Essentials Book now available.

Purchase a copy of Red Hat Enterprise Linux 9 (RHEL 9) Essentials

Red Hat Enterprise Linux 9 Essentials Print and eBook (PDF) editions contain 34 chapters and 298 pages

Preview Book

Chapter 1. System requirements

This chapter lists system requirements for successfully running virtualization on Red Hat Enterprise Linux. You require a system running Red Hat Enterprise Linux 5 Server with the virtualization packages. The host needs a configured hypervisor . For information on installing the hypervisor, read Chapter 4, Installing Red Hat Virtualization packages on the host .
Minimum system requirements
  • 6GB free disk space
  • 2GB of RAM.
You want to virtualize three guests running application XYZ on Red Hat Enterprise Linux. Red Hat Enterprise Linux 5 requires 5GB of disk space and application XYZ requires 2GB of disk space. Red Hat Enterprise Linux requires a minimum of 512MB of RAM application XYZ requires up to 256MB of RAM. Application XYZ runs best on just one processing core.
The minimum system requirements for a system running application XYZ on three Red Hat Enterprise Linux guests are:
21GB of free disk space available to the host,
2304MB(768GB x 3) + 1024MB(for the host) = approximately 3.5GB of RAM, and
3 processing cores + 1 for the host(for better performance).
Example 1.1. Requirements for a hypothetical virtualization system

There are additional requirements for para-virtualization and full virtualization.
Para-virtualization requirements
Para-virtualized guests require the Red Hat Enterprise Linux 5 installation tree available over NFS, FTP or HTTP.
Full virtualization requirements
Full virtualization requires DVD, CD-ROM or bootable .iso file installation media.
Full virtualization requires CPUs with hardware virtualization extensions. This section describes how to identify hardware virtualization extensions and enable them in your BIOS if they are disabled. If hardware virtualization extensions are not present you can only use para-virtualization with Red Hat Virtualization.
The virtualization extensions can not be disabled in the BIOS for AMD-V capable processors installed in a Rev 2 socket. The Intel® VT extensions can be disabled in the BIOS. Certain laptop vendors have disabled the Intel® VT extensions by default in their CPUs.
These instructions verify whether the Intel® VT virtualization extensions are enabled or if the instructions are disabled in BIOS:
  1. Run the xm dmesg | grep VMX command. The output should display as follows:
    (XEN) VMXON is done
    (XEN) VMXON is done
  2. Run the cat /proc/cpuinfo | grep vmx command to verify the CPU flags have been set. The output should be similar to the following. Note vmx in the output:
    flags   : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush 
    dts acpi mmx fxsr sse sse2 ss ht  tm syscall lm constant_tsc pni monitor ds_cpl
    vmx est tm2 cx16 xtpr lahf_lm
Do not proceed if the output of xm dmesg | grep VMX is not VMXON is done for each CPU. Please visit the BIOS if other messages are reported.
The following commands verify that the virtualization extensions are enabled on AMD-V architectures:
  1. Run the xm dmesg | grep SVM command. The output should look like the following:
    (XEN) AMD SVM Extension is enabled for cpu 0
    (XEN) AMD SVM Extension is enabled for cpu 1
  2. Run the cat /proc/cpuinfo | grep svm to verify the CPU flags have been set. The output should be similar to the following. Note svm in the output:
    flags   :  fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush
    mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt lm 3dnowext 3dnow pni cx16
    lahf_lm cmp_legacy svm cr8legacy ts fid vid ttp tm stc
The virtualization extensions are sometimes disabled in BIOS, usually by laptop manufacturers. Refer to Section 28.12, “Enabling Intel VT and AMD-V virtualization hardware extensions in BIOS” for instructions on enabling disabled virtualization extensions.
Storage support
The supported guest storage methods are:
  • files on local storage,
  • physical disk partitions,
  • locally connected physical LUNs,
  • LVM partitions, and
  • iSCSI and Fibre Channel based LUNs.

File based guest storage

File based guest images should be stored in the /var/lib/xen/images/ folder. If you use a different directory you must add the directory to your SELinux policy. For more information see Section 10.1, “SELinux and virtualization”.

  Published under the terms of the GNU General Public License Design by Interspire